/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.dtstack.flink.api.java;

import org.apache.flink.annotation.Public;
import org.apache.flink.api.common.InvalidProgramException;
import org.apache.flink.api.common.JobExecutionResult;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.configuration.RestOptions;
import org.apache.flink.configuration.TaskManagerOptions;
import org.apache.flink.runtime.jobgraph.JobGraph;
import org.apache.flink.runtime.jobgraph.SavepointRestoreSettings;
import org.apache.flink.runtime.minicluster.MiniCluster;
import org.apache.flink.runtime.minicluster.MiniClusterConfiguration;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.graph.StreamGraph;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.annotation.Nonnull;
import java.net.URL;
import java.util.Collections;
import java.util.List;

/**
 * The LocalStreamEnvironment is a StreamExecutionEnvironment that runs the program locally,
 * multi-threaded, in the JVM where the environment is instantiated. It spawns an embedded
 * Flink cluster in the background and executes the program on that cluster.
 *
 * <p>When this environment is instantiated, it uses a default parallelism of {@code 1}. The default
 * parallelism can be set via {@link #setParallelism(int)}.
 *
 * @author jiangbo
 */
@Public
public class MyLocalStreamEnvironment extends StreamExecutionEnvironment {

    private static final Logger LOG = LoggerFactory.getLogger(org.apache.flink.streaming.api.environment.LocalStreamEnvironment.class);

    private final Configuration configuration;

    public List<URL> getClasspaths() {
        return classpaths;
    }

    public void setClasspaths(List<URL> classpaths) {
        this.classpaths = classpaths;
    }

    private List<URL> classpaths = Collections.emptyList();

    private SavepointRestoreSettings settings;

    public void setSettings(SavepointRestoreSettings settings) {
        this.settings = settings;
    }

    /**
     * Creates a new mini cluster stream environment that uses the default configuration.
     */
    public MyLocalStreamEnvironment() {
        this(new Configuration());
    }

    /**
     * Creates a new mini cluster stream environment that configures its local executor with the given configuration.
     *
     * @param configuration The configuration used to configure the local executor.
     */
    public MyLocalStreamEnvironment(@Nonnull Configuration configuration) {
        if (!ExecutionEnvironment.areExplicitEnvironmentsAllowed()) {
            throw new InvalidProgramException(
                    "The LocalStreamEnvironment cannot be used when submitting a program through a client, " +
                            "or running in a TestEnvironment context.");
        }
        this.configuration = configuration;
        setParallelism(1);
    }

    @Override
    protected Configuration getConfiguration() {
        return configuration;
    }

    /**
     * Executes the JobGraph of the on a mini cluster of CLusterUtil with a user
     * specified name.
     *
     * @param jobName
     *            name of the job
     * @return The result of the job execution, containing elapsed time and accumulators.
     */
    @Override
    public JobExecutionResult execute(String jobName) throws Exception {
        // transform the streaming program into a JobGraph
        StreamGraph streamGraph = getStreamGraph();
        streamGraph.setJobName(jobName);

        JobGraph jobGraph = streamGraph.getJobGraph();
        jobGraph.setClasspaths(classpaths);

        if (settings != null){
            jobGraph.setSavepointRestoreSettings(settings);
        }

        Configuration configuration = new Configuration();
        configuration.addAll(jobGraph.getJobConfiguration());
        configuration.setString(TaskManagerOptions.MANAGED_MEMORY_SIZE.key(), "512M");
        configuration.setInteger(TaskManagerOptions.NUM_TASK_SLOTS, jobGraph.getMaximumParallelism());

        // add (and override) the settings with what the user defined
        configuration.addAll(this.configuration);

        if (!configuration.contains(RestOptions.BIND_PORT)) {
            configuration.setString(RestOptions.BIND_PORT, "0");
        }

        int numSlotsPerTaskManager = configuration.getInteger(TaskManagerOptions.NUM_TASK_SLOTS, jobGraph.getMaximumParallelism());

        MiniClusterConfiguration cfg = new MiniClusterConfiguration.Builder()
                .setConfiguration(configuration)
                .setNumSlotsPerTaskManager(numSlotsPerTaskManager)
                .build();

        if (LOG.isInfoEnabled()) {
            LOG.info("Running job on local embedded Flink mini cluster");
        }

        MiniCluster miniCluster = new MiniCluster(cfg);

        try {
            miniCluster.start();
            configuration.setInteger(RestOptions.PORT, miniCluster.getRestAddress().get().getPort());

            return miniCluster.executeJobBlocking(jobGraph);
        }
        finally {
            transformations.clear();
            miniCluster.close();
        }
    }
}
